Assembly device, especially welder



April 12, 1949.

Filed May 10, 1947 w. A. WEIGHTMAN 2,466,668

ASSEMBLY DEVICE, ESPECIALLY WELDER ll Sheets$heet l f? W Q 1' Q H 2? is;INVENTOR WLULam QWeigktmarL A7 a BY/mmfimg ATTORNEY April 12, 1949.

W. A. WElGHTMAN ASSEMBLY DEVICE, ESPECIALLY WELDER Filed May x0, 1947'11 Sheets-Sheet 2 INVENTOR \NLHiam sQWeLqhtmcm A TTORNE Y April 12, 949.w. A. WEIGHTMAN ASSEMBLY DEVICE, ESPECIALLY WELDER l1 Sheets-Sheet 3Filed May 10, 1947 I N V EN TOR wiuiam QWaqMman 8 YM [fla ATTORNEY April12, 1949. w, wElGHTMAN 2,466,668

ASSEMBLY DEVICE, ESPECIALLY WELDER Filed May 10, 1947 ll Sheets-Sheet 4INVENTOR i ATTORNEY April 12, 1949. w. A. WEIGHTMAN 2,466,668

ASSEMBLY DEVICE, ESPECIALLY WELDER Filed May 10, 1947 i I llSheets-Sheet 5 INVENTOR Wmmm QWeig himar A TTORNE Y April 12, 1949. w.A. WEIGHTMAN 2,466,668

ASSEMBLY DEVICE, ESPECIALLY WELDER Filed May 10} 1947 11 Sheets-Sheet eD 55 52 51, 51, 55 I I I| k 1} I H II II 1| I {1' I u n Hi WLUL Qm *QWeLgKhnuu BYMZ fla A TTORNE Y April 12, 1949. w. A. WEIGHTMAN I ASSEMBLYDEVICE, ESPECIALLY WELDER ll Sheets-Sheet 7 Filed May 10, 1947IIIIIIIIIIIIIIIII/ PICK? IN V EN TOR ATTORNEY Alglil 12, 1949. wWEIGHTMAN 2,466,668

ASSEMBLY DEVICE, ESPECIALLY WELDER Filed May 10, 1947 11 Sheets-Sheet 8INVENTOR q; 1 U 8 William *HWe'tg Mman BY 1- had:

ATTORNEY April 12, 1949. w, WEIGHTMAN 2,466,668

ASSEMBLY DEVICE, ESPECIALLY WELDER Filed May 10, 1947 11 Sheets-$heet 9INVENTOR L56 wiumms weighfmfl k 31 M Z M April 12, 1949.

w. A. w EEEEEE AN 2,466,668

ASSEMBLY DEVICE ESPECI ill! N W 1 liclmv kweigcman BY M,

ATTORNEY April 1949. w. A. WEIGHTMAN 2,466,668

' ASSEMBLY DEVICE, ESPECIALLY WELDER Filed May 10, 1947 l1 Sheets-Sheet11 I N V EN TQR W11 ham QWzai g hr mam A TTORNE Y Patented Apr. 12, 1949UNITED STATES PATENT OFFICE 21 Claims.

The invention refers to a machine for assembling and securing metalparts and especially to a machine in which the connecting of theassembled co-mponent parts of a beam structure is done by an electricspot welder. More particularly, the invention relates to a machine forspot Welding together elongated sheet metal profiles into a heavy beamas used for the center sill of a railway car.

An object of the invention is to provide a machine of the indicated typewhich holds the parts entering into the construction in accuraterelative location during the assembling operation.

Another object is to provide a machine permitting the assembly of allprofiles entering into a beam structure in a single continuousoperation.

A still further object is to provide a machine which, after the initialset-up has been made, performs the connecting operations over the lengthof the beam or the like automatically so as to require merelysupervision and the performance of a few manual operations by workmen.

Another object is to provide a machine which connects the componentparts by a great number of welds of uniform and predetermined quality soas to give the welded structure the strength and other physicalqualities required, a feature which is obviously of great importance insuch highly stressed structures as a center sill of a railway car.

A further object is to provide a machine of the indicated type which isof relatively simple construction, which is durable and rugged and whichis easy to operate.

Amon the objects is also to provide a machine of the indicated typeadapted to be used for a variety of diiierent forms and sizes of membersto be assembled.

A more specific object is to provide a machine for Welding togetherflanged sheet metal profiles into a channel section center sill of arailway car in which the profiles are connected by outwardly projectingflanges as well as by parts which overlap each other in the interior ofthe sill.

The foregoing objects and further objects and advantages of theinvention are achieved accordin to the invention by providing a weldingmachine having a welding unit movable relative to the profiles formingthe component parts of a beam, which machine is provided with means forholding the component profiles accurately positioned relatively to eachother, these profileholding means being also movable relatively to suchprofiles.

combination of assembling means for holding the profiles in the requiredpositions relatively to each other and to the Welding unit at pointsremote from the location of the welding unit.

A still further feature of the invention resides in the arrangement andiormation of the welding electrodes so as to permit their entry into theinterior oi the hollow sill as Well as their automatic operation withoutinterference with each other.

Further objects, advantages and features of the invention will beunderstood from consideration of the fOllOWlllg detailed description andattached drawing, in which Figure 1 is a small-scale diagrammatic sideelevation of the entire machine with a beam to be assembled shown inlace;

Figure 2 is a side elevation of the welding unit of the machine togetherwith a part of the beam to be assembled and part of the supportingstructure for the machine;

Figure 3 is an end elevation of the unit shown in Figure 2 viewed in thedirection of the arrows on line 3-3 of Figure 2, certain parts of themachine, the sill held in it and the supporting rails being shown insection;

Figure 4 is a fragmentary section on a larger scale along line l4 ofFigure 2;

Figure 5 is a longitudinal vertical section through the welding unitalong line 5-5 of Figure 3 Figure 6 is a vertical transverse fragmentarysection along line B6 of Figure 5 on a larger scale;

Figure 7 is a fragmentary vertical transverse section along line l-'l ofFigure 5 on the scale of Figure 6 showing one pair of the horizontalelectrodes;

Figure 8 is a fragmentary vertical transverse section alon line 38 ofFigure 2 on a larger scale showing details of the gear and drivingmechanism for moving the welding unit on its supporting rails;

Figure 9 is a fragmentary horizontal section along line 53-49 of Figure8;

Figure 10 is a fragmentary side elevation of part of the machine shownin Figure 2 but on a larger scale showing the indexing mechanism formoving the welding unit step-by-step from one welding station to thenext;

Figure 11 is a fragmentary plan view and section along line I ll l ofFigure 10;

Figure 12 is an elevation of one of the work supports together with thesupporting structure in section along line IZ-IZ of Figure 1 but on aAnother feature of the invention resides in the 56 much larger scale;

Figure 13 is a fragmentary transverse sectional view of part of thestructure illustrated in Figme 12 with certain portions broken away toillustrate the interior structure;

Figure 14 is a side elevation partly in section along line il-ll ofFigure 12, showing in full lines the work support folded down and inphantom lines the lower part of the welding unit and the work support inupright position;

Figures 15 and 16 are fragmentary sections along the correspondinglynumbered lines of Figure 12;

Figure 17 is a fragmentary section along line ll'l'| of Figure 14; and

Figure 18 is a diagram of the electrodes and of the operating system forthe electrodes.

Secured to the floor 2i are a pair of transversely spaced rails 22provided with stops 23 at their ends. Between and parallel to the railsare arranged two I-sections 24 each carrying on its outside a rack 25.Carried by and movable on the rails 22 is a welding machine unit 25carrying pinions 21 (Figure 3) meshing with the racks 25. Longitudinallyspaced devices or jigs 29 are supported by the sections 24 swingablyabout individual transverse axes til, and these jigs 29 in turn supportthe work 28, which has the form of a long beam.

The invention is illustrated as applied to the welding of a channelsection beam 28 to be used for a center sill of a railway car. This beamis assembled in the machine in upside-down position; it has side walls3| provided with bottom flanges 32 which overlap the marginal portion ofan outer bottom member 33 while an inner bottom member 34 overlaps theouter bottom memher and by marginal flanges 35 the inside of the sidewalls 3i. The two bottom members 33 and 34 are each provided with aninwardly projecting longitudinal channel 36, and these channels areinternested. The three members 3f, 33 and 34 constituting the beam maybe formed of sheet metal on a draw bench. The sheet metal may be coldrolled austenitic stainless steel or another high-strength material. Thesections entering into the beam are held prior to and during the weldingoperation in a predetermined position by the supports 29 and by parts ofthe welding unit 26, as will be described in detail later on.

The welding unit has a rigid frame comprisillg longitudinally andvertically extending side members El, 38 interconnected by a lowertransverse member 39 and an upper transverse member 36. This frame issupported on the rails 22 by two pairs of wheels 4! which are freelyrotatable in bearings of the side frames 37, 38.

Brackets 42 secured to the front and back of the supporting frame carrydevices 43 including rollers 44, 45, 46 and fill for insuring the exactrelative positions of the beam members 3!, 33 and 34. The cylindricalhorizontal rollers 44 press on the outside of the bottom member 33 abovethe side walls 3! while the rollers 45 and 46 are arranged at about l5degrees and press into the corners between side walls 3i and flanges 32and between the inner bottom member 34 and its flanges 35. The otherhorizontally arranged rollers ll press against the side walls 3| neartheir free margins.

The top rollers 44 are each supported in a member 48 held in place byslide and bolt connections 49 and are vertically adjustable by screws 58so as to insure the correct relative adjustment of the different rollersand the desired pressure on'the members of the workpiece.

Obviously, the devices 43 hold the workpieces in the exact desiredposition relative to each other and to the welder unit while permittingunrestricted movement of the welder unit and the workpieces in thelongitudinal direction of the latter. Between the two devices 43 arearranged the devices for connecting the sections of the beam with eachother, which devices are, in the shown embodiment, pairs of spot weldingelectrodes, which will now be described.

Arranged in a transverse row and supported by the upper transverse framemember M; are five hydraulic cylinders, a central cylinder 5i and twopairs of outwardly adjacent cylinders 52 and 53. The piston rods ofthese cylinders carry welding electrodes 54, 55 and 56 respectively.

A similar series of hydraulic cylinders El, 52 and 53 are supported bythe lower transverse frame member 39 and have their piston rodsconnected with welding electrodes 5d, 55 and 58' respectively alignedwith the correspondingly numbered aforesaid upper electrodes.

The piston rod of cylinder Si is surrounded by the member or bracket 57forming a rigid part of the machine frame and servin for guiding on astraight vertical path members 58 inserted between the piston rods ofthe cylinders 52 and the appertaining electrodes 55. The electrode 54'is, in turn, guided on the aforesaid members 58. Inserted between theouter electrodes lit and their piston rods are members til guided forvertical up and down movement on brackets 6! of the side frame members31, 38. The arrangement and form of the lower electrode supportingmembers is such as to clear the workpiece and to permit free passagethereof through the machine when not engaged by the electrodes duringthe welding operations.

From Figure 6 it is apparent that the electrodes so far described areadapted for making five welds in a single position of the weld unit; onepair of welds between the flanges 32 of the side walls 3| and themargins of the outer bottom member 33, one pair of welds between themarginal horizontal portion of the inner bottom member 35 and theoverlapping portions of the bottom member 33, and one weld between theoverlapping bottom walls of the channel section portions 36. How thesewelds are sequentially made will be described later on.

A horizontal shaft 62 is provided on each side of the Welding unit nearthe respective side frames 31, 38. Each of these shafts 62 carriesswingably a pair of U-formed yokes 53, 64 (see Figures 5, '7 and 18).The inner arm of each of these yokes carries electrodes 65, 66respectively, while the outer arms are connected with a cylinder El, 67,the pistons of which carry electrodes 68, E9 respectively. Theelectrodes 65, 63 and 66, 69 are aligned with each other. It should benoted that the electrodes 65, 68 are designed for engagement with theside walls 3i and the fiange 35 of the inner bottom wall near the freemargins of said flanges while the electrodes 86, 69 are designed forengagement with the same members near the horizontal portions of thebottom walls of the workpiece. In other words, the electrodes 65, 68 and66, 69 are designed for effecting at a given position of the weldingunit relative to the workpiece on each side of the latter two welds,which are offset relative to each other in vertical and longitudinaldirection. It should also be observed that the axes of the horizontalelectrodes are spaced in the longitudinal direction of the workpiecefrom the vertically arranged electrodes described hereinbefore.

The inner arms of the yokes 63, 64 are shaped to clear the workpieces soas to permit lengthwise free passage of the workpiece through thewelding unit. On account of the swivel suspension on the shafts 62, thehorizontal electrodes may engage the workpiece unrestrictedly from bothsides if pressure is applied to the cylinders 67, 61, as Will bedescribed more fully later on. If the pressure is released and theelectrodes 68, 69 are withdrawn, then the electrodes 65, 66 becomedisengaged from the workpiece on account of the arrangement of the shaft92 on the outside of the center of gravity of the yokes 93, GA causingthe inner arms of the yokes to move down under the influence of theirown weight, thereby movin the electrodes out of contact with theworkpiece. For such clearance, but a slight swivel movement of the yokes93 is necessary. Further swivel movement is prevented by the adjustablestops Ill engaging projections 75 of the yokes.

All the electrodes on the one side of the machine and the centralelectrodes 54, 54 are connected by bus bars to the secondary of onewelding transformer I2, all electrodes on the other side of the machineare connected by bus bars to the secondary of a second transformer l3.Some of these bus bars and their connections to the electrodes are shownin the drawing at i l, 75 and i6, IT. A diagrammatic outline of theelectrical connections is shown in Figure 18 and will be explained lateron in the description of the operation of the machine.

The pressure medium for operating the hydraulic cylinders is supplied bya pump 18 driven by an electric motor 79. This pump and its drive, aswell as a storage tank for the pressure medium, will likewise not bedescribed in detail, as they may be of conventional design.

The weldin unit is provided with two devices for moving it along itstrack 2!, one device for moving it by equal increments from one Weldingstation to the next, and another device for moving it withoutinterruption from one position to another remote position; e. g., formoving it from the end position back to the initial position for startinwork on another beam. Both devices work on the pinions 2'! meshing withthe racks 25 as briefly mentioned in the beginning of this description.

The hereinbeiore described pinions 21 are keyed to verticalframe-supported shafts BI which are drivingly connected by bevel ears 82to a horizontal transverse shaft 83. On the side of the frame member 31,the shaft 83 has keyed to it a pinion 84 and the free end of the shaft83 may be squared at 85 permitting rotation by means of a removablecrank (not shown). A shaft 86 is supported by the machine frame at adistance from and parallel to the shaft 83 and is rigidly connected witha regular gear 81 and a ratchet gear 88. Supported for swivel movementabout the axis of shaft 36 is a member 89 carrying a pair of meshinggears 99, 9|. The gear 90 is in permanent engagement with the aforesaidgear 8! while the gear 9I is free from direct engagement with the gear81. The member 89 has an extension 92 with a spring biased plug 93adapted for engagement with one of three holes 94 of a bracket 95rigidly supported by the machine frame. The arrangement is such that inone position, the position shown in full lines in Figures 2 and 9, thegear 9!] meshes directly with the gear of pinion 84 on the shaft 83While in the other extreme position, when the plug 93 engages theuppermost hole 94, the gear 9! meshes with the gear 84. Consequently, inthe first position, rotation of the gear 87 will drive the gear 84 inone direction, while rotation of the gear 81 in the same direction withthe second postion of the gears 90, 9!, will cause the gear 84 to bedriven in the opposite direction. In the middle position, that is, whenplug 93 engages the central hole 94, both gears and 9! are out ofengagement with the gear 84 so that no driving connection exists withthe gear 81.

A second member 96 is supported for swivel movement about the shaft 88and is provided with a plurality of pawls 91 adapted for engagement withthe teeth of the ratchet wheel 88 in one direction while sliding overthe teeth when rotated with the body 96 in the opposite direction. Thepawls are so arranged that at least one of them will engage one of theteeth at a certain initial position of the member 95 so as to avoid lostmotion and take care of small inaccuracies of the ratchet wheel 88 or ofthe movement of the member 96.

The member 96 is journalled at 98 to the rod 99 of a piston movable in acylinder I00 which, in turn, is journalled at IOI to the machine frame.The solenoid valve I92 serves for admitting a pressure medium to thecylinder in front or in back of the piston. If fluid is admitted to theouter end of the cylinder, then the piston will be pushed outward andturn the ratchet wheel correspondingly, thereby moving the welding unitalong its tracks a corresponding increment if one of the gears 90 or BIis in engagement with the gear 84. By varying the size of the gears orby varying the stroke of the piston, the length of each increment can beadjusted to fit the specific requirement. The illustrated machine may,for example, be designed for a fixed step-by-step movement of two inchescorresponding to the distance between longitudinally adjacent welds ineach area.

The other end of shaft 89, that is, the end supported by the side frame38, carries one element of a clutch I03 which may be operated by a leverI04. The other element of the clutch is in driving connection with anelectric motor I05 over a reduction gear I06. If the gears 90, 9| are inthe middle or neutral position, then the welding unit may be driven anydistance along its tracks through the motor I05 while the coupling I04is engaged.

Provision is preferably made for preventing the simultaneous engagementof the two driving means with the shaft 83. This may be done by a switch(not shown) for cutting out the electric motor unless the support 89 forthe step-by-step drive is in the middle or neutral position.

Mechanism is also carried by the machine for operating the electrodes inpredetermined sequence, for supplying them with welding current and foroperating the indexing transport when all the electrodes have gonethrough one cycle of welding operations. These details of the machinewill be described later in connection with the operation of the entiremachine.

The shafts 30 carrying the work supports 29 are swingable in bracketsIU'I secured to the I- beams 24. In the following, but one of thesupports will be described, as all of them are alike.

Each support has a transverse member I08, upstanding arms I09, H0 and atransverse portion III extending downwardly beyond the shaft 30. Avertical member H2 adapted for engagement with the channel sections 36of the work is secured to the cross member I08 while the lateralportions of this cross member are adapted for supporting the flanges onthe free margins of the side walls 3I of the workpieces.

The arms I09 and III! of the work support carry swingably about verticalshafts H3 members I I4 adapted in one position for firm engagement withthe outside of the side walls 3I and the underside of the upper sidewall flanges 42. When turned 90 degrees in one direction or the otherfrom the position shown, for instance, in Figures 12 and 15, that is,into one of the positions indicated by phantom lines in Figure 15, thewing members H4 are entirely outside the confines of the workpieces.Swingable latches H5 supported in the side members I09, III] andmatching notches I I6 in the hub portions of the wing members H4 servefor holding the wing members either in the operative work-engaging or inone of the inoperative positions.

A cross member III has its one end hinged to a projecting pin H8 of thearm I06 while its other end is adapted for engagement by a screw H9threaded into a yoke I20, which latter is swingably supported at I2I bythe other arm H0. The cross member II! is provided with projections I22adapted for engagement with the outside of the bottom plate 33 so as topress it firmly against the flange of the side wall and the latteragainst the top of the wing H4. A central adjustable bolt I23 on memberIII is adapted for engagement with the outside of the channel section 36so as to press the two bottom wall members, 33, 34 firmly together andagainst the support IIZ.

In the upright position shown in Figure 12, the supports 29 areconsequently adapted for accurately and firmly holding the differentpieces of the beam to be assembled in accurate relative position and atthe exact height necessary for proper engagement by the electrodes ofthe welding machine.

On the other hand, it is evident that the supports 29 in the positionshown in Figure 12 are in the path of the welding unit 26. For thisreason, the machine is designed so that the supports 29 can be foldeddown about their supporting shafts 36 into the position shown in fulllines in Figure 14 where the welder unit, in spite of the downwardlyextending portions of its side frames and the relatively low arrangementof its cross members and shafts 39, 83, may pass over themunobstructedly. Such temporary removal of one of the supports isunobjectionable because its clamping and supporting functions are takenover by the hereinbefore described devices 43 on the welder unit.

For individually raising the supports 29 or for folding them down, eachshaft 30 carries freely rotatably a gear sector I24 on one side whichmeshes with a rack I25 guided for longitudinal back and forth movementin brackets I25 secured to one of the I--beams 24. The individual racksfor the different supports 29 are interconnected by rods I21 and at oneend by a rod I28 to the piston rod of a hydraulic cylinder I29 adaptedfor moving all racks together backand forth with their interconnectingrods I21, I23. The ends of the cylinder I29 communicate with conduitsI33 for a pressure medium controlled by four-way valves I3I, one each atthe location of each support 29. The arrangement is such that theoperation of any one of the valves I3I permits pressure medium to beadmitted to one or the other end of the cylinder for moving the racksback or forth.

The pressure medium may be derived from any appropriate source. Each ofthe supports 29 may be individually coupled with or uncoupled from itsgear sector i24. For this purpose, the lower depending portion III ofeach support I29 carries a transverse slidable pin or rod I32. This rodI32 is toothed at I33 over part of its length and this toothed portionis engaged by a pinion I34 carried by a square-ended operating shaftI35. Each sector I24 is provided with two holes I36 spaced degrees fromeach other with respect to the axis of the shaft 30 and at the samedistance from this axis as the rod I32 so that one end of the rod I32may be projected into either one of these holes.

If a support 29 is folded down as shown in Figure 14 and the gear sectorI24 brought into the position illustrated in the same figure in fulllines by appropriate movement of the rack I25, then the rod I32 may beprojected into the upper hole I36, whereupon admission of pressure fluidto the outer end of the cylinder I29 will cause the rack to move to theright (Figure 14) rotating the sector E24 counterclockwise, the lattertaking through the rod I32 the support 29 along until it assumes theupright position shown in phantom lines. Hereupon, the rod I32 may bemoved out of engagement with the gear sector I24, whereupon its otherend engages the hole in a bracket II-ll secured to the opposite I-beamThis latter operation secures the support in the upright position whilefreeing the gear sector and the racks from the particular support so asto allow the desired movement of any other support 29.

The provision of two holes I36 at a distance of 90 degrees permits thefolding down of the supports 29 in either direction with a gear sectorof slightly more than 90 degrees and with a correspondingly short rack.It will thus be noted that the uncoupling of the support 29 and its gearI24 causes automatic engagement of the support with the supportingstructure so as' to hold it in upright position.

After the welding unit has been moved to one end of its tracks '22, thesupports 29 are secured in upright position and the members of a beam tobe connected by welding are secured in the supports 29 in properrelative adjustment. During or after this arrangement of the beammembers, the latter are threaded into the guiding device 43 at one endof the welder unit so that they end closely adjacent the weldingelectrodes.

With the clutch I83 released and the lever 89 set for step-by-stepmovement in the direction toward and along the work 28, the operatingand welding mechanism of the welding unit is set in motion.

The control mechanism for the automatic operation of the machinecomprises a continuously driven shaft indicated in Figure 18 by the lineI49. For an electrode and transformer arrangement as illustrated in thedrawing, this shaft I40 carries five cams MI, I42, I43, I44, I45 eachoperating on a hydraulic valve I4I, I42, I43, I44, I45. These valves areadapted for admitting a pressure medium from supply conduits I46 througha system of distributing conduits I41 to the respective coordinatedcylinders 5|, 5| to 53, 53' and 61, ill for moving the differentelectrodes. It will be noted that always two cylinders of two pairs ofelectrodes connected with different transformers are controlled by oneof the cam operated valves.

Each time a set of electrodes is brought into engagement with the workthrough the actuation of one of the valves, one of a number of cams IIto I55 on shaft I actuates one of the switches I5! to I55, and therebyenergizes over an appropriate welding timer I56 the respectiveelectrodes.

After all the valves and individual switches have once been actuated, afurther cam I56 on shaft I40 energizes the solenoid valve I02 causingone forth and back movement of the piston of cylinder I00 (Figure 2),thereby causing the movement of the welder unit one increment along itstracks into the next welding position, whereupon the cycle of weldingoperations is automatically repeated.

Provision is made for preventing the fiow of welding current throughsome of the electrodes not yet in engagement with the work or alreadypast engagement with the work at the ends of the workpieces to beunited. This may be done by switches I51, I58, I59. The switch I5! isarranged in series with the aforesaid switches l5l, I52, I53, that is,the three switches that feed the vertical electrodes arranged in onetransverse plane. The switch I58 is inserted in series with the switchI54 that feeds the electrodes carried by the yokes 63 and the switch I59is inserted in the circuit feeding the electrodes on yoke 64.Ordinarily, these switches are held in closed position by spring biasedlevers I60. At each end of the tracks 22, the free ends of the levers Iengage an elongated cam IEI. tudinally adjustable on a bracket I62secured to one of the beams 24 (Figure 3). As long as the levers I65engage these cams IBI, the switches I51, I58, I59 are held open and nocurrent can fiow through the electrodes in spite of the operation of thehydraulic valves and the different switches I5I to I. The cams arelongitudinally adjusted so that they will release the respective leversI and thereby permit closing of the electric circuits when therespective electrodes reach the work. At the other end of the travel ofthe welder unit, the cam I6I will engage the levers I50 so as to cut offthe current as soon as the electrode in one transverse plane leaves thework.

It will be obvious to those skilled in the modern art of electricwelding that only a very diagrammatic outline of the electric system hasbeen given and that actually the electrical system is quite complicatedand comprises additional switches and devices for automatically stoppingthe machine when the work on one workpiece is completed, for cutting outthe continuous automatic operation of the hydraulic valves and so on. Inview of what constitutes the subject matter of the present invention andin view of the fact that the indicated details in different forms areavailable in the art, no further disclosure in this respect isnecessary.

While a single embodiment of the invention is illustrated and described,it should be understood that the invention is subject to modificationsand adaptations which will easily occur to those skilled in the art andthat protection is sought for the invention as covered by the spirit andthe language of the attached claims.

What is claimed is:

1. In a machine for assembling a plurality of elongated profiles into abeam, a unit provided with means for, effecting a series of connectionsThis cam is longibetween said profiles, means for supporting said unit,means for relatively moving said unit and said supporting means, andmeans on said unit for holding the profiles in their predeterminedrelative position to each other and to the unit during the performanceof the connecting operations by said unit.

2. In a machine for connecting a plurality of elongated profiles alongtheir length for forming a beam, a unit provided with means foreffecting a series of connections between said profiles, means forsupporting said unit movably along said profiles, and means on said unitfor holding the profiles in their predetermined relative position toeach other and to the unit during the performance of the connectingoperations by said means provided on said unit.

3. In a machine for connecting together a plurality of profiles into abeam structure, a frame, means for movably supporting said frame along apredetermined path, means on said frame for making successively theconnections between said profiles, and means on both sides of saidlastnamed means for guiding and supporting said profiles inpredetermined position relative to each other and the frame.

4. In a machine for welding together a set of profiles into a beamstructure, a frame, means for movably supporting said frame along a predetermined path, a plurality of welding electrodes on said frame, andmeans arranged in the direction of said path on both sides of saidelectrodes for guiding and supporting a set of profiles in predeterminedposition relative to the electrodes.

5. In a machine for connecting several profiles with each otherthroughout their lengths, a stationary track, a structure movablysupported on said track, means on said structure for making successivelythe connections between the profiles, a plurality of supports located atintervals along the length of said track and designed for supporting theprofiles to be connected at a predetermined height and in apredetermined relative position to each other, means for bodily removingsaid supports from the profiles so as to permit the passage of saidstructure, and means on said structure for temporarily holding saidprofiles at said predetermined height and position relative to eachother during the connecting operations while one of said units in therespective region is removed from the profiles.

6. Machine according to claim 5 in which said supports each as a singleunit are arranged between said tracks and are supported swingably aboutaxes extending transversely to and near said tracks so as to fold downfor the passage of said structure over them.

7. In a machine for connecting by electric spot welding a plurality ofprofiles into an open channel section beam, said profiles havingoverlapping parts in the plane of the bottom wall and overlapping partsin the planes of the side walls of the channel section, a weldin unitcomprising a structure relatively movable along said profiles, pairs ofwelding electrodes supported and guided for linear movement by saidstructure for effecting welds between the overlapping parts of theprofile in the plane of the bottom wall of the channel section, pairs ofelectrodes for efiecting the welds between the overlapping parts in theplanes of the side walls of the channel section, a plurality of yokeseach supporting one pair of the last-named electrodes and supported bysaid structure swingably about. an axis extending par= allel to thedirection of the movement of the unit, and means for keeping theelectrodes and the yokes supporting them out of contact with theworkpiece during the intervals between welding operations.

8. In a machine for connecting by electric spot welding a plurality ofprofiles into an open channel section beam, said profiles havingoverlapping parts in the plane of a side wall of the channel section, awelding unit comprising a structure relatively movable along saidprofiles, a pair of electrodes for efiecting said welds, a yoke supporting said electrodes and supported by said structure swingably aboutan axis extending parallel to the direction of the movement of the unitrelative to the profiles, and means for keeping the electrodes and theyoke supportin them out of contact with the workpiece during theintervals between welding operations.

9. In a welding machine according to claim 8 having means on one arm ofsaid yoke for moving one of the electrodes relative to the yoke whilethe other electrode is rigidly supported by the other arm of the yoke,the center of gravity being disposed on the same side of the axis as thefixedly supported electrode whereby the fixedly supported electrode willswing away from the work upon retraction of the movable electrode.

10. In a welding machine according to claim 8 having means on one arm ofsaid yoke for moving one of the electrodes relative to the yoke whilethe other electrode is rigidly supported by the other arm of the yoke,the center of gravity being disposed on the same side of the axis as thefixedly supported electrode whereby the fixedly supported electrode willswing away from the work upon retraction of the movable electrode, and astop on said frame designed for engaging said yoke so as to limit themovement of the yoke under the infiuence of its weight whereby furtherretraction of the movable electrode will cause it to stand clear of thework.

11. In a machine for efiecting a plurality of connections betweenelongated profiles throughout the length of the latter, a stationarytrack, a structure movably supported on said track and provided withmeans for successively effecting said connections, and motor drivenmeans on said structure engaging stationary means for selectively movingsaid structure step by step through predetermined increments along thetrack and for selectively moving it any desired distance on said trackwithout interruption.

12. In a machine for effecting a plurality of connections betweenelongated profiles throughout the length of the latter, a stationarytrack, a structure on said track provided with means for effectingsuccessively said connections, driving means on said structure drivinglyconnected with stationary means extending along said track, a firstmotor driven means on said structure for imparting step-by-step movementa second motor driven means, for imparting continuous movement, andmeans for alternatively coupling one of said motor driven means to saiddriving means for selectively moving respectively said structure in aseries of predetermined increments and continuously any desired distanceon said track.

13. A machine accordin to claim 11 in which said first motor drivenmeans comprises a reciprocating prime mover while said second motordriven means comprises a rotating motor.

14. In a machine for'connecting a plurality of profiles throughout theirlength, a plurality of supports for the profiles longitudinally spacedfrom each other, individual means on each of said supports for swingingthe latter away from the profiles, motor means common to all of saidsupports for swinging the supports into engagement and out of engagementwith the profiles, and individual means on the individual supports andon said motor driven means adapted for individually connecting eachsupport with the motor driven means and for disconnecting it therefromso that with one motor driven means all supports may be movedindividually.

15. In a machine according to claim 14 which includes a plurality ofindividual control means for said motor, one of said control means beingarranged adjacent to each one of said supports.

16. Support for holding a plurality of profiles in a predeterminedposition preparatory to their connection with each other, said supportcomprising a member swingably supported about a horizontal transverseaxis by stationary bracket means, a gear segment supported swingablyabout the same axis independently of said member, a rack horizontallymovably supported in stationary means and in meshing engagement with thegear segment, a motor for moving the rack back and forth, means forcoupling said member to segment and for uncoupling it therefrom.

17. In a machine for connecting a plurality of profiles throughout theirlength, a plurality of supports for the profiles longitudinally spacedfrom each other, individual means on each of said supports for swinginthe latter away from the profiles, motor means common to all or saidsupports for swinging the supports into engagement and out of engagementwith the profiles, and individual means on the individual supports andon said motor driven means adapted for individually connecting eachsupport with the motor driven means and for disconnecting it therefromso that with one motor driven means all supports may be movedindividually, and a stationary means designed for engagement by saidcoupling means upon disengagement thereof from the gear segment so as tohold said member in upright position.

18. In a spot welding machine comprising a welding unit movable alongelongated workpieces to be welded together and comprising a series ofWeiding tools arranged in planes spaced from each other in the directionof movement, means for automatically activating said electrodes in apredetermined sequence, and a separate means for each set of electrodesarranged in one plane for preventing the activation of such electrodesprior to and after their engagement with the workpieces.

19. In a spot welding machine, a weldin unit movably supported on atrack, means for supporting an elongated workpiece parallel to saidtrack, a plurality of welding electrodes arranged in several planesspaced from each other in the direction of the movement of the unit onsaid tracks, means for automatically moving mated electrodes toward eachother and for supplying them with welding current, at least one switchfor each set of electrodes arranged in one plane, and means governed bythe movement of the unit along said track for operating said switches soas to prevent the supply of weldin current to the respective electrodesbe'fore the latter are in juxtaposition to the work at the start of anoperation of the machine and after such electrodes have left the work attheend of an operation.

20. A welding machine for an elongated work- 10 Number 14 21. A weldingmachine as set forth in claim 20 in which said pressure devices arerollers.

WILLIAM A. WEIGH'IMAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Name Date 2,190,692 Bitter et a1 Feb. 20, 19402,339,826 Weightman Jan. 25, 1944

